Pump



May 26, 1970 J. HASQUENOPH E AL 3,514,221

PUMP

Filed June 7, 1968 2 Sheets-Sheet 1 INVENTOR 9 .TER/V mu Malawi, mm: mum/v ATTORNEYS y 1970 J. HASQUENOFH ET AL 3,514,221

PUMP

2 Sheets-Sheet 2 Filed June 7, 1968 MM J 3mm m m g Q w mm IM A N M w. BY H B 4 w n 0 j.

United States Patent 3,514,221 PUMP Jean Hasqnenoph, Lagny, and Marc Pouliquin, Paris, France, assignors to Commissariat a lEnergie Atomique, Paris, France, an organization of France Filed June 7, 1968, Ser. No. 743,577 Claims priority, applicatgon France, Sept. 7, 1967,

Int. Cl. F04b 23/04 1/14; F04c 15/00 US. Cl. 417-406 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to pumping devices (pumps and compressors), that is to say to devices in- I tended to transfer a fluid from an inlet conduit to an outlet conduit, possibly after having modified the pressure of this fluid.

It has already been proposed in French Pat. No. 1,494,951 filed in the name of Commissariat a IEnergie Atomique on Aug. 4, 1966 and granted on Aug. 7, 1967, to make the pumping devices in question comprise: a fixed casing comprising a wall limited interiorly by a surface in the form of a spherical crown, and, at the interior of this wall, a trunconical annular surface centred at the centre of this crown and having the same axis as this crown; a hub mounted in the casing in a manner to be able to pivot about that axis and connected to a drive shaft; a wobble member mounted on this hub in a manner to be able to pivot with respect to the hub about an axis cutting the axis of the hub at the centre mentioned above, this member comprising a trunconical surface centred at said centre and adapted to roll on the trunconical surface of the casing by fitting against that surface along a straight line segment; a piece connected to one of the two trunconical surfaces and limited exteriorly by a surface, in the form of a spherical crown centred at the centre mentioned above, disposed conjointly along the circle which limits interiorly the other trunconical surface; a partition extending in an axial plane between two radially opposite portions of the two spherical crowns in a manner to isolate permanently one from the other the two volumes disposed, on opposite sides of this partition, both between these portions and between the adjacent trunconical surface portions; a slot provided in at least one of the two trunconical surfaces in a manner to provide an axial passage for the partition; an inlet conduit and an outlet conduit opening respectively in the two above mentioned volumes on opposite sides of the partition; means for preventing the wobble member from rotating about its axis; and a bellows interconnecting in a fluid-tight manner an annular portion of the casing and an annular portion, of the wobble member, disposed preferably at the interior of the interior spherical crown.

An object of the present invention is to provide a pumping device having a plurality of stages which is of relatively small volume and in which the pumped (or compressed) fluid remains totally isolated from the bearings and other members subjected to greasing and, preferably in addition, from the atmosphere.

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According to the principal feature of the present invention, a pumping device of the type described above comprises in addition: cylinders having axes parallel to the axis of the hub and disposed in the part, of the fixed casing, situated, with respect to the wobble member, on the side opposite to the side where the trunconical surface of the casing is located; pistons mounted slidably in these cylinders; rods connecting these pistons to the wobble member; and means for making the outlet of the pumping stage formed by the two above-mentioned volumes of trunconical deformation communicate with at least one of these cylinders, preferably by passing through appropriate openings provided on the one hand in the wobble member and on the other hand in the piston corresponding to this cylinder.

The connections between the rods and the wobble member and/or between the rods and the pistons are preferably assured with the aid of ball and socket joints protected by bellows for maintaining the fluid tightness, these bellows being preferably metallic and welded at their two ends on the rod, on the wobble member and/or on the piston.

One embodiment of the invention will now be described, by way of non-limiting example, with reference to the accompanying drawings. The features that are going to be described with respect to this embodiment should be considered as forming part of the invention, but it should be understood that any equivalent features could also be used without departing from the scope of the invention.

In the drawings:

FIGS. 1 and 2 show-respectively in axial section along I-I of FIG. 2, and in transverse section along II-II of FIG. 1, a compressor established according to the invention; and

FIGS. 3 and 4 show two details of this compressor.

This compressor comprises a first stage identical to the pumping device described in the French patent mentioned above: this stage, of the rotary-rocking or wobble type, comprises a casing 1 into which the fluid to be compressed is admitted through a conduit 2 and out of which it is evacuated through a conduit 3, this transfer being generated by a wobble member 4 connected to a rotary drive shaft '5.

The casing 1 comprises:

A wall limited interiorly by a surface 7 having the form of a spherical zone of centre 0 and of axis AB extending symmetrically on both sides of a diametrical plane, and

At the interior of the surface 7, a piece having a trunconical face 9 centred at O and of axis AB.

A hub 10 rigid with the shaft 5 is mounted in the casing 1 with the aid of bearings 11 in a manner to be able to rotate about its axis, which coincides with the axis AB.

The wobble member 4 comprises:

A sleeve 4 mounted with the aid of bearings 12 on a bent extension 10 of the hub 10 in a manner to be able to rotate about an axis CD inclined with respect to the axis AB and cutting this latter axis at the point 0,

A trunconical surface 13 centred at O and of axis CD adapted to come into contact with the surface 9 along a line segment of generatrix s, and

A wall limited exteriorly by a surface 15, in the form of a spherical zone centred at O and of axis CD, adapted to move conjointly opposite the circular interior edge of the surface 9.

A fixed partition 16 extends along an axial plane between two opposite portions of the two surfaces 7 and 15 and passes through an opening 17 provided in the member 4.

The annular working chamber, delimited by the two spherical surfaces 7 and 15 and by the two trunconical surfaces 9 and 13, is divided into two compartments by this partition 1-6 and by the junction by the two trunconical surfaces 9 and 13 along the line segment s.

The two conduits 2 and 3 open into these two compartments on opposite sides of the partition 16.

A fluid-tight and flexible bellows 20, in particular metallic, interconnects in a fluid-tight manner an annular piece 22, of the casing 1, disposed about the hub 10, and an annular piece 21, of the member 4, disposed at the interior of the surface 15. This bellows is here chosen sufficiently rigid in rotation to prevent, by itself, rotation of the member 4.

FIG. 1 also shows:

Annular joints or rings 29, 30, assuring fluid tightness between the spherical surfaces 7, 15, and the opposite surfaces with which they cooperate,

Dynamic balancing masses 31, 32 of the rotary ensemble formed by the shaft and the bent hub 10, and

An electric driving motor whose stator 33 is mounted in the casing 1 and whose rotor 34 is rigid with the shaft 5.

To the first pumping stage that has just been described is added, according to the invention, at least one second stage of the barrel type taking advantage of the conical or wobbling movement of the member 4 to couple to this member 4 the piston-rods 35 of the pistons 36 sliding in the cylinders 37 having axes parallel to the axis of the shaft 5.

Needless to say, the coupling in question is arranged in a manner not to make a hole in the walls of the working chamber of the first stage: in other words, the cylinders 36 are disposed in the part, of the casing 1, disposed axially, with respect to the wobble member 4, on the side opposite to the side where this working chamber is located.

The rods 35, which work alternately in traction and in compression, must be undeformable longitudinally. Each of these rods 35 is connected to the member 4 and to one of the pistons 36 in a manner to transform with a minimum resistance the conical wobble (without rotation) of this member into longitudinal reciprocation of this piston.

Moreover, it is in general advantageous to avoid any contact between the pumped fluid and the connecting members, especially when these connecting members comprise pieces coacting in relative motion, possibly with the interposition of a lubricant.

In a preferred embodiment, each rod 35 is connected in a rigid manner to the corresponding piston 36 and with the aid of a ball and socket joint to the member 4: for this purpose each rod end disposed on the side of this member 4 is terminated by a ball 38 (FIG. 4) which is imprisioned in a complementary cage 46 rigid with the member 4, the ball-cage ensemble being itself protected by a fluid-tight metallic bellows 39 whose two ends are welded, directly or not, respectively to the rod and to the member 4. The lubrication of this ball and socket joint is assured for life by the introduction of grease into the cage 46. In such an embodiment, in order to render possible the slight oscillations of the piston 36 (and of the rod 38 which is rigid with this piston) during wobbling of the member 4, it is suflicient to provide between this piston and the cylinder 37 in which it slides only one sealing piston ring 47 of small axial dimension, this piston ring then forming a sort of pivot for these oscillations.

Of course, a ball and socket joint coupling could also be provided at each of the two ends of each rod.

-It should be noted that each of the bellows 20 and 39 undergoes only slight flexions of the conical type in this sense that, with respect to one of the terminal bases considered as fixed, its other terminal base undergoes solely the flexions corresponding to a conical gravitation of its 4 axis about the axis of this fixed base, to the exclusion of any other deformations of compression, expansion or torsion.

Thus these bellows can present without difiiculty a long longevity.

In practice, they are advantageously formed of a sheet of stainless steel whose thickness is comprised between 0.1 and 0.5 millimeter, this sheet being first of all put in the form of a tube by rolling and by welding the juxtaposed edges, and being then deformed into a bellows by hydraulic pressure.

The mean diameter of these bellows is in general comprised between 5 and 20 centimeters, the radial dimension of each wave being of the order of a quarter of the radius, and its axial dimension of the order of an eighth of the radius, and each wave having approximately the form of an S composed of two semi-circles connected by parallel rectilinear portions.

In the case in which two ball and socket joints are used for each piston rod 35, instead of using two bellows corresponding respectively to these two ball and socket joints, a single bellows can be used for each rod, enveloping this rod entirely, the two ends of this single bellows being connected in a fluid-tight manner, preferably by welding, on the one hand to the member 4 and on the other hand to the corresponding piston: such a variant is particularly advantageous when the rods are short. In such a case, it can be opportune not to fold the central zone of the bellows, which is then formed by a rigid tube connected to two folded portions.

As in conventional barrel type compressors, the active volumes of the cylinders 37 are served by inlet valves 48 (FIG. 2) and outlet valves 49 actuated automatically by the reciprocation of the pistons and disposed so that the fluid drawn into one of these volumes is then delivered towards the exterior of the machine or into another, smaller volume, for its subsequent compression.

It is this latter solution which has been adopted in the gas compressor illustrated.

In this gas compressor, the casing 1 comprises five cylinders 37 regularly distributed about the axis of the shaft 5. The compressed gas exiting at 3 (FIG. 3) from the first stage is admitted (according to the arrows 40, FIGS. 1 and 2) into two of the cylinders 37 through valves 41 provided in the corresponding pistons 36. Then the gas compressed in these two cylinders is delivered (according to the arrows 42) into a third single cylinder of the same diameter as the two preceding cylinders, and, from there, successively, into a fourth cylinder of smaller diameter (according to the arrows 43) and into a fifth cylinder of still smaller diameter (according to the arrows 44) from where it is evacuated highly compressed at 45.

Thus the gas drawn in at 2 undergoes successively before its outlet from the machine at 45 five compressions: the first compression is generated in the first trunconical deformation stage of this machine, exactly as in the known compressor of the conical or wobbling type of the French patent mentioned above; the slightly compressed gas resulting from this first compression is collected in the buffer volume situated between the wobble member 4 and the pistons 36 and it is drawn out of this volume successively into the four other stages of the machine which are formed respectively by the two first cylinders, the third, the fourth and the fifth cylinders (as in a conventional barrel compressor).

It should be noted that this quintuple compression is obtained with a compact machine of very small overall size: the general umbrella form of the first stage is very harmoniously completed by the general bell form of the ensemble of the following stages and by the housing of the driving motor at the centre of this bell.

It will also be observed that, due to the presence of the bellows 20 and possibly of the bellows 39, the compressed gas remains totally separated from the volumes containing the various bearings, grease reserves, mutually sliding pieces and electrical members, which constitutes an important advantage, in particular when the gas is toxic, even radioactive, and/or when it is compressed.

Many variants of the embodiment described above are possible.

What we claim is:

1. A pumping device comprising: a fixed casing comprising a wall limited interiorly by a surface in the form of a spherical crown, and, at the interior of this wall, a trunconical annular surface centered at the centre of said crown and having the same axis as said crown; a hub mounted in said casing in a manner to be able to pivot about said axis, said hub being connected to a drive shaft; a wobble member mounted on this hub in a manner to be able to pivot with respect to said hub about an axis cutting the axis of said hub at said centre, said member comprising a trunconical surface centred at said centre and adapted to roll on the trunconical surface of the casing and fitting against said trunconical surface of the casing along a straight line segment; a piece connected to one of the two trunconical surfaces and limited exteriorly by a surface, in the form of a spherical crown centred at said centre, disposed conjointly along the circle which limits interiorly the other trunconical surface; a partition extending in an axial plane between two radially opposite portions of the two spherical crowns in a manner to isolate permanently one from the other the two volumes disposed, on opposite sides of this partition, both between said portions and between the adjacent trunconical surface portions; a slot provided in at least one of the two trunconical surfaces in a manner to provide an axial passage for said partition; an inlet conduit and an outlet conduit opening respectively into said two volumes on opposite sides of the partition; means for preventing the wobble member from turning about its axis; a bellows interconnecting in a fluid-tight manner an annular piece of the casing and an annular piece, of the wobble member, disposed preferably at the interior spherical crown; cylinders having axes parallel to the axis of the hub and disposed in the part, of the fixed casing, situated, with respect to the wobble member, on the side opposite to the side where the trunconical surface of this casing is located; pistons mounted slidably in these cylinders; rods connecting these pistons to the wobble member; and communication means for making the outlet of the trunconical deformation pumping stage formed by said two volumes communicate with at least one of said cylinders, said communication means between the trunconical deformation stage and the cylinder comprising an opening formed in the wobble member in the vicinity of the partition and a valve provided in the piston corresponding to this cylinder.

2. A pumping device comprising: a fixed casing comprising a wall limited interiorly by a surface in the form of a spherical crown, and, at the interior of this wall, a trunconical annular surface centred at the centre of said crown and having the same axis as said crown; a hub mounted in said casing in a manner to be able to pivot about said axis, said hub being connected to a drive shaft; a wobble member mounted on this hub in a manner to be able to pivot with respect to said hub about an axis cutting the axis of said hub at said centre, said member comprising a trunconical surface centered at said centre and adapted to roll on the trunconical surface of the casing and fitting against said trunconical surface of the casing along a straight line segment; a piece connected to one of the two trunconical surfaces and limited exteriorly by a surface, in the form of a spherical crown centred at said centre, disposed conjointly along the circle which limits interiorly the other trunconical surface; a partition extending in an axial plane between two radially opposite portions of the two spherical crowns in a manner to isolate permanently one from the other the two volumes disposed, on opposite sides of this partition, both between said portions and between the adjacent trunconical surface portions; a slot provided in at least one of the two trunconical surfaces in a manner to provide an axial passage for said partition; an inlet conduit and an outlet conduit opening respectively into said two volumes on opposite sides of the partition; means for preventing the wobble member from turning about its axis; a bellows interconnecting in a fluid-tight manner an annular piece of the casing and an annular piece, of the wobble member, disposed preferably at the interior of the interior spherical crown; cylinders having axes parallel to the axis of the hub and disposed in the part, of the fixed casing, situated, with respect to the wobble member, on the side opposite to the side where the trunconical surface of this casing is located; pistons mounted slidably in these cylinders; rods connecting these pistons to the wobble member, the connection between each rod and the wobble member (and/ or between each rod and the corresponding piston) being assured by a ball and socket joint comprising a ball rigid with the rod and a cage rigid with the wobble member (or with the piston), said ball and socket joint being protected by a bellows, preferably metallic, for maintaining fluid-tightness; and communication means for making the outlet of the trunconical deformation pumping stage formed by said two volumes communicate with at least one of said cylinders.

3. A pumping device according to claim 2, characterized in that each rod is rigid with the corresponding piston and is connected by a ball and socket joint to the wobble member, slight oscillations of the piston being rendered possible by the interposition of only a single piston ring of small axial dimensions between this piston and the corresponding cylinder.

References Cited UNITED STATES PATENTS 773,206 10/1904 Hall 12358 1,715,735 6/1929 Banning 103173 1,819,966 8/1931 Olson 230-186 2,027,076 1/ 1936 Volliman 230-181 2,141,057 12/1938 Whiles 230l81 2,887,059 5/1959 Cornelius 103133 3,131,855 5/1964 Kocher 230181 3,323,466 6/1967 Ford 103133 FOREIGN PATENTS 245,099 8/ 1910 Germany.

WILLIAM L. FREEH, Primary Examiner US. Cl. X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent NO. Dated 26,

Inventor(s) Jean Hasquenoph and Marc Pouliquin It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 6, delete "Sept." and insert June Edwardllnetdlmh I.

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